With the rapid development of wired and wireless networks, more and more users are seeking video services, including video streaming and video conferencing over the Internet. However, the Internet does not provide guaranteed quality of service (QoS). Traffic congestion usually results in the loss of data packets. A lost packet/frame is detected when a next data packet or image frame is received while the previous data packet or image frame has not been received for a certain time. In wireless networks, packet losses happen frequently due to multi-path fading, shadowing and noise disturbance of wireless channels. Although existing error concealment techniques can typically deal with the loss of macroblocks, existing error concealment techniques cannot adequately reconstruct or handle the loss of an entire frame.
Frame loss is commonplace in video transmission, typically resulting in severe distortions to decoded/reconstructed video data. To save transmission overhead, one data packet may carry information for an entire video frame. Thus, loss of a single packet in a low bit rate application may result in loss of an entire frame. Additionally, and in high bit rate applications, traffic congestion may cause a burst of packet/frame losses. Moreover, and to make matters worse, if a spatial-temporal predictive coding scheme is utilized to achieve high compression efficiency, an erroneously recovered block (due to packet/frame loss) may lead not only to errors in the subsequent blocks in the same frame, but also propagate errors to subsequent frames.